You can't change the past. Or at least, you shouldn't.

Sloane Becker is haunted by the events of one night three years ago—the night her friendship with her best friend ended. But when strange things start to happen around Sloane, she realizes that she has the ability to manipulate time—even travel back to that terrible night.

She's not the only time traveler out there, though. A community of other travelers exists, with one main rule guiding them: don't alter the past. This doesn't stop Sloane from wishing she could fix that one night. Nor does it stop the mysterious woman who seems to be stalking her through time, trying to kill her.

As Sloane struggles to master her newfound abilities, as well as her complex relationship with her mysterious coworker Eric, something keeps pulling her back, over and over again, to that night everything went wrong. Sloane knows she shouldn't do anything to change the past—but what if her choices have already been written into that story?